What Is Reliability Psychology?

The psychology industry constantly evolves as research provides a more significant understanding of how the human mind functions. In the 21st century, the field of social psychology can offer more insight into the various processes that occur as individuals process events on emotional, mental, and physical levels. Reliability in psychology refers to the consistency of research results, which is often vital to ensure that findings are as accurate and all-encompassing as possible. This standard is meant to maintain a level of consistency in psychology research.

Reliability psychology

When it concerns psychological testing and research, the term reliability refers to the consistency of a research study or measuring test. To understand what makes reliability important, we can look at a scale as an example. If you are weighing an item on different scales, you might expect to get the same results every time. If a scale had the ability to give a different result every time you weighed the same item, it would be useless and wouldn't be considered a reliable measuring device. 

The same logic is often true of research findings in psychology. If the findings of a research study can be replicated consistently, they may be considered reliable. A correlation coefficient can be used to assess the degree of reliability such that a psychological test should have a high positive correlation to be considered reliable. There are several ways of measuring the reliability of psychological testing and research, including inter-rater reliability, test-retest reliability, and internal consistency.

Inter-rater reliability is considered an important gauge of the reliability of subjective evaluations. Sometimes called inter-observer reliability, this measurement assesses the consistency with which different raters or observers agree on their assessment decisions. For example, if multiple psychologists provide the same diagnosis to a patient, inter-rater reliability is high; if the psychologists provided different diagnoses, inter-rater reliability may be lower. If the raters are inconsistent or the inter-rater reliability is otherwise poor, that may be an indication that the test may result in lower-quality data collection. 

Since factors or situations change, and individuals might not always act the same in every instance that research is replicated, some difference in results may be expected. However, a strong positive correlation between the results could indicate that the test or research is reliable. Psychologists might use terms like "strong" or "weak" to describe the trustworthiness of the results of a study. If there aren't enough studies on a topic, further research might be suggested at the conclusion of a study. 

Different types of psychological reliability: Internal and external

Within psychology, there are two forms of reliability: internal and external. Both are often necessary to determine the true reliability of a research test. 

Internal reliability refers to the assessment of result consistency across different items within the test itself. It is the extent to which a measure is consistent within itself. External reliability is the extent to which a measure will vary from one use to the next. Therefore, internal and external reliability allow you to understand the reliability of the test itself, both from its components and how it compares when testing different items.

Assessing reliability: Internal and external methods

There are several methods that are used on tests to assess reliability, including the following:

The split-half method 

The first is associated with internal reliability and is known as the split-half method. This method assesses the internal consistency of a test. Internal consistency refers to the extent to which all the test parts contribute equally to what is being measured.

Often, you can compare the results of one half of the test against the other half. You can do so by dividing the test into the first and second halves or using an odd and even method. When doing so, look for similar results from both test halves.

If you have a test that is not coming back as highly reliable, using a split-half method can be a way to determine what value the test has, where it's weak, and what improvements can be made to the methodology to create a more substantial reliability factor.

The parallel-form method 

Parallel-form reliability evaluates different questions that seek to assess the same construct. This type of evaluation can be done in combination with other methods, including split-half. For example, a researcher might develop a large set of questions, divide them in half, and then administer them randomly to half of the sample. 

The test-retest method 

Another option to test the reliability of any research is the test-retest method. Used to assess external consistency, the test-retest method measures a test’s stability, comparing results over time. A typical assessment using this method may involve giving participants the same test at two different times. If the results are similar both times, then test-retest reliability may be established.

When you work with the test-retest method, obtaining consistent results can be difficult because there may have to be a long period between the two assessments. In addition, you may find that if you retest too quickly, participants might end up remembering information from the last test, which could result in biased results.

What is the connection between reliability and validity?

Researchers use concepts other than reliability when determining if research is viable. They may also look for validity, which is tied to the credibility or believability of the research. In validity studies, you may be looking at whether the research findings are genuine and whether there are valid relationships between the variables that could lead to a credible conclusion.

Different research methods can vary in terms of the level of validity they produce. The more structured and controlled an experiment is, the higher the internal validity. However, that same structure and control could give it a much lower external validity score.

Observable research, on the other hand, may be higher in external validity because it has real-world variables. Still, those real-world variables mean there could be multiple uncontrolled variables, which might create a low internal validity score. When you have so many uncontrolled variables, you might not be certain what variables impact the behaviors you observe in your subjects.

Two aspects of reliability and validity

As with reliability, there are two primary forms of validity. The first is internal validity; like reliability, the internal aspect focuses on the instruments and procedures to determine if they measure what they need to measure.

Think about a study that is trying to measure stress. The participants might be shown photos of different war atrocities, and after the test, they might be asked how the pictures made them feel. If they respond that they felt disturbed or stressed, then there is validity that the photos are stress producers.

External validity, on the other hand, means the results can be generalized beyond the initial study. It might apply to those who aren't in the sample of the study participants. One example could be higher education-related research that focuses on determining the best study methods for college students. These tests could assess methods like cramming compared to studying over time (or other techniques.) In the end, the test would need to apply to multiple subjects and expand beyond the initial sample of the research itself.

Some of the tests available for verifying the validity of research include content-related and criterion-related evaluations. Content-related validity can be determined by the face test, which asks the question, "Does the test appear to test what it aims to test?" Another option is the construct validity test, which asks, "Does the test relate to underlying theoretical concepts?"

The goal of criterion-related validity testing is to test the relationship between what's being studied and other measures. The first aspect of criterion-related testing is concurrent validity, which asks, "Does it relate to an existing similar measure?" Secondly, the predictive validity of criterion-related testing asks, "Does the test predict later performance on a related criterion?"

Reliability vs. validity

If the scores on a test are wildly different every time the participants take the test, then the test might be unlikely to make a valid prediction. Even if a test is reliable, it does not automatically mean it is valid. For example, a researcher might not measure someone's strength as a measure of their intelligence. The two are not related and would not create a valid conclusion.

Reliability is a necessary condition for validity if you have a valid test, but it alone is not a sufficient reason to call a test valid. As a body of research is built, the validity is demonstrated in the relationship between the test and the behavior it is intended to measure. A valid test also ensures that test results accurately reflect the dimension undergoing assessment.

Psychological counseling options 

Psychological studies have led to the development of over 400 therapeutic modalities in psychotherapy. These developments have also led to the invention of online counseling, which allows more clients to receive support from home while being able to take control of their treatment format. Studies have also supported the efficacy of online counseling, with hundreds of researchers finding it effective, cost-effective, and sometimes better than in-person counseling. 

Online therapy

With an online platform like BetterHelp, you can meet with licensed providers at any time and receive worksheets, professional resources, and journaling prompts to support your treatment plan. In addition, you don't have to have a mental health diagnosis or severe symptoms to see a therapist. Many counselors offer support for those who have not received a diagnosis. These support methods include providing a personality test, helping with daily challenges, addressing stressful situations, and dealing with interpersonal issues.